US20260039268A1 - Filter device and antenna device - Google Patents

Filter device and antenna device

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Publication number
US20260039268A1
US20260039268A1 US19/351,353 US202519351353A US2026039268A1 US 20260039268 A1 US20260039268 A1 US 20260039268A1 US 202519351353 A US202519351353 A US 202519351353A US 2026039268 A1 US2026039268 A1 US 2026039268A1
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United States
Prior art keywords
inductor
filter device
outer electrode
path
capacitor
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
US19/351,353
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English (en)
Inventor
Shinya Tachibana
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Murata Manufacturing Co Ltd
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Murata Manufacturing Co Ltd
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Publication date
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Publication of US20260039268A1 publication Critical patent/US20260039268A1/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/175—Series LC in series path
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/0115—Frequency selective two-port networks comprising only inductors and capacitors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/09—Filters comprising mutual inductance
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1758—Series LC in shunt or branch path
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1775—Parallel LC in shunt or branch path
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/70—Multiple-port networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
    • H03H9/72—Networks using surface acoustic waves
    • H03H9/725—Duplexers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H1/00—Constructional details of impedance networks whose electrical mode of operation is not specified or applicable to more than one type of network
    • H03H2001/0021—Constructional details
    • H03H2001/0085—Multilayer, e.g. LTCC, HTCC, green sheets

Definitions

  • the present disclosure relates to a filter device and an antenna device.
  • Patent Document 1 when an attenuation band (attenuation pole) due to parallel resonance and a passband due to series resonance are close to each other, it is difficult to maintain both the attenuation characteristic and the bandpass characteristic at high levels.
  • the present disclosure has been made to address such a problem and is aimed at providing a filter device with which good characteristics can be obtained even when an attenuation band due to parallel resonance and a passband due to series resonance are close to each other.
  • a filter device has an attenuation band.
  • the filter device includes a first terminal, a second terminal, a first inductor connected to the first terminal, and a series resonator disposed in a first path out of the first path and a second path provided in parallel with each other between the first inductor and the second terminal.
  • the series resonator includes a second inductor, a capacitor connected in series with the second inductor, and a third inductor connected in series with the second inductor and the capacitor. Magnetic coupling between the first inductor and the third inductor is weaker than magnetic coupling between the first inductor and the second inductor.
  • An antenna device configured to be able to radiate a radio wave.
  • the antenna device includes a radiating element, a feeding circuit configured to feed a radio-frequency signal to the radiating element, and the above-described filter device provided between an antenna and the feeding circuit.
  • the series resonator is disposed in the first path, and the first inductor and the second inductor are magnetically coupled to each other.
  • FIG. 1 is a perspective view of a filter device according to Embodiment 1.
  • FIG. 2 includes circuit diagrams of the filter device and an antenna device according to Embodiment 1.
  • FIG. 3 illustrates an attenuation characteristic of the filter device.
  • FIG. 4 is an exploded plan view illustrating the configuration of the filter device according to Embodiment 1.
  • FIG. 5 is a perspective view of a filter device according to Embodiment 2.
  • FIG. 6 is an exploded plan view illustrating the configuration of the filter device according to Embodiment 2.
  • FIG. 7 is a graph illustrating the attenuation characteristic of the filter device according to Embodiment 2.
  • FIG. 8 is a perspective view of a filter device according to Embodiment 3.
  • FIG. 9 is an exploded plan view illustrating the configuration of the filter device according to Embodiment 3.
  • FIG. 10 is a graph illustrating the attenuation characteristic of the filter device according to Embodiment 3.
  • FIG. 11 includes circuit diagrams of an antenna device according to Modification 1.
  • FIG. 12 includes circuit diagrams of an antenna device according to Modification 2.
  • FIG. 13 includes circuit diagrams of an antenna device according to Modification 3.
  • FIG. 1 is a perspective view of a filter device 100 according to Embodiment 1.
  • the short edge direction of the filter device 100 is defined as the X direction
  • the long edge direction of the filter device 100 is defined as the Y direction
  • the height direction of the filter device 100 is defined as the Z direction.
  • the filter device 100 is a rectangular parallelepiped-shaped chip component in which two inductors and a single capacitor are laminated in the Z direction.
  • the filter device 100 includes an insulating body 3 formed by laminating a plurality of insulating substrates (insulating body layers) on which first conductor patterns of a first inductor L 1 , second conductor patterns of a second inductor L 2 , and electrode patterns of a capacitor C 1 are formed as illustrated in FIG. 1 .
  • the laminating direction of the insulating substrates is the Z direction, and the arrow direction indicates an upper layer direction.
  • the insulating substrates are formed of a material such as, for example, an insulating material mainly including borosilicate glass or insulating resin such as alumina, zirconia, or polyimide resin.
  • a material such as, for example, an insulating material mainly including borosilicate glass or insulating resin such as alumina, zirconia, or polyimide resin.
  • interfaces between the plurality of insulating substrates are not necessarily clarified due to processing such as firing and solidification.
  • Outer electrodes 4 a (first outer electrodes) and outer electrodes 4 b (second outer electrodes) as illustrated in FIG. 1 are formed at two positions in the Y direction in the insulating body 3 of the filter device 100 .
  • the insulating body 3 has a pair of main surfaces that face each other.
  • the lower main surface illustrated in FIG. 1 is a mounting surface that faces a circuit board. According to Embodiment 1, the lower main surface illustrated in FIG. 1 is referred to as a bottom surface, and the upper main surface illustrated in FIG. 1 is referred to as a top surface.
  • Electrode patterns of the outer electrodes 4 a and the outer electrodes 4 b are formed not only on the bottom surface of the insulating body 3 but also on the side surfaces connecting the main surfaces of the insulating body 3 .
  • the outer electrodes 4 a and the outer electrodes 4 b form a U shape.
  • the outer electrodes 4 a provided on the respective side surfaces (a first side surface and a second side surface) of the insulating body 3 facing each other are at the same potential due to the electrode pattern provided on the bottom surface of the insulating body 3 .
  • the outer electrodes 4 b provided on the respective side surfaces of the insulating body 3 facing each other are at the same potential due to the electrode pattern provided on the bottom surface of the insulating body 3 .
  • a first conductor pattern 1 a (first conductor pattern) of the first inductor L 1 and the outer electrode 4 a are electrically connected to each other via a wiring pattern 11 a at the side surface of the insulating body 3 .
  • An electrode pattern 5 b (second electrode pattern) of the capacitor C 1 and the outer electrode 4 b are electrically connected to each other via wiring patterns 51 a (see FIG. 4 ) and 51 b at the side surface of the insulating body 3 .
  • a third inductor L 3 includes a path extending from the wiring patterns 11 b and 11 d provided at a first end of the first inductor L 1 through the outer electrode 4 b on the side surface (first side surface) of the insulating body 3 , the electrode pattern 5 c of the capacitor C 1 , and the outer electrode 4 b on the side surface (second side surface) of the insulating body 3 , to the wiring pattern 21 e provided at a first end of the second inductor L 2 . Opening surfaces of the first inductor L 1 and the second inductor L 2 forming coils are formed so as to be parallel to the XY plane, and the openings are superposed on each other when seen in plan view seen from the top surface side.
  • the second inductor L 2 , the third inductor L 3 , and the capacitor C 1 are connected in series in the insulating body 3 and included in an LC series resonator. Accordingly, the filter device 100 produces an attenuation pole by using the LC series resonator and has a resonant frequency.
  • a circuit configuration of the filter device 100 and an antenna device using the filter device 100 are described in detail.
  • FIG. 2 includes circuit diagrams of the filter device and the antenna device according to Embodiment 1.
  • (a) is a circuit diagram of the filter device 100 according to Embodiment 1
  • (b) is a circuit diagram of an antenna device 150 according to Embodiment 1.
  • the filter device 100 is a trap filter that is used for the antenna device 150 , blocks the passage of radio-frequency signals of a specific frequency band, and attenuates the radio-frequency signals of a specific frequency band.
  • the filter device 100 is also referred to as a band eliminate filter.
  • the antenna device 150 includes a feeding circuit RF 1 , the filter device 100 , and a radiating element 155 .
  • the antenna device 150 is mounted on, for example, a mobile terminal such as a cellular phone, a smartphone, or a tablet, or a communication device such as a personal computer with a communication function.
  • the feeding circuit RF 1 is configured to feed radio-frequency signals in a frequency band of the f1 band to the radiating element 155 .
  • the radiating element 155 is, for example, a monopole antenna and able to radiate the radio-frequency signals of the f1 band fed from the feeding circuit RF 1 into the air as radio waves.
  • the filter device 100 includes a terminal P 1 and a terminal P 2 .
  • the terminal P 1 is provided for connecting the filter device 100 to a transmission line on the feeding circuit RF 1 side.
  • the terminal P 2 is provided for connecting the filter device 100 to a transmission line on the radiating element 155 side.
  • the terminal P 1 (first terminal) corresponds to the outer electrodes 4 a illustrated in FIG. 1 .
  • the terminal P 2 (second terminal) corresponds to the outer electrodes 4 b illustrated in FIG. 1 .
  • the terminal P 1 serves as an input terminal and the terminal P 2 serves as an output terminal.
  • the terminal P 1 serves as an output terminal and the terminal P 2 serves as an input terminal.
  • the magnetic coupling between the first inductor L 1 and the third inductor L 3 is weaker than the magnetic coupling between the first inductor L 1 and the second inductor L 2 , and may approach zero depending on the physical layout.
  • a mutual inductance M is generated between the first inductor L 1 and the second inductor L 2
  • the mutual inductance M is not generated between the first inductor L 1 and the third inductor L 3 .
  • the LC series resonator RS is provided on the first path TL 1 and the parallel resonator includes the first path TL 1 and the second path TL 2 , the resonant frequency of the parallel resonator is coincident with the serial resonant frequency f0 of the LC series resonator RS and becomes the parallel resonant frequency of the attenuation band (f0 band) of the filter device 100 .
  • the serial resonant frequency f0 of the LC series resonator RS is determined by the inductances of the inductors (the second inductor L 2 and the third inductor L 3 ) included in the LC series resonator RS and the capacitance of the capacitor (capacitor C 1 ).
  • the inductor included in the LC series resonator RS may be increased.
  • a layer on which a second conductive pattern being part of the second inductor L 2 is formed may be added.
  • the distance between the first inductor L 1 and the second inductor L 2 reduces, and a coupling coefficient k unintentionally increases.
  • reduction of the coupling coefficient k allows the serial resonant frequency (center frequency) to become closer to the parallel resonant frequency (center frequency).
  • the second inductor L 2 is increased or the capacitance of the capacitor C 1 is increased.
  • a region where the opening portions of the first and the second inductors L 1 and L 2 and the electrode of the capacitor C 1 are superposed on each other in plan view seen from the top surface side may increase and block the magnetic flux.
  • graph I represents the attenuation characteristic of the filter device when the coupling coefficient k is a certain value.
  • the attenuation characteristic of the filter device changes to graph II and the width of the attenuation pole increases.
  • the width of the attenuation pole also changes depending on the quality factor of the second inductor L 2 .
  • graph I represents the attenuation characteristic of the filter device when the quality factor of the second inductor L 2 is a certain value.
  • the attenuation characteristic of the filter device changes to graph III and the width of the attenuation pole reduces.
  • the inductance of the first inductor L 1 influences the bandpass characteristic at every frequency.
  • a passage loss improves on the high bandwidth side of the resonant frequency f0 in a direction indicated by an arrow illustrated in FIG. 3 .
  • the filter device 100 in consideration of the above-described relationships, the third inductor L 3 not magnetically couple to the first inductor L 1 is provided other than the second inductor L 2 . In this way, the inductance of the inductors included in the LC series resonator RS can be increased.
  • the filter device 100 allows the reduction of the resonant frequency f0 without changing the coupling coefficient k between the first inductor L 1 and the second inductor L 2 , and the steep filter device having the attenuation pole in the low frequency band can be realized.
  • FIG. 4 is an exploded plan view illustrating the configuration of the filter device 100 according to Embodiment 1.
  • the first conductor patterns 1 a to 1 d , the second conductor patterns 2 a to 2 d , the wiring patterns 11 a to 11 b , 21 e , 51 c , 52 c , and 52 to 56 , and the electrode patterns 5 a to 5 c are formed on insulating substrates 3 a to 3 n by a printing method.
  • the first conductor pattern 1 a being part of the first inductor L 1 is formed on the insulating substrate 3 a .
  • the first conductor pattern 1 a is a hexagonal pattern of about a single counterclockwise loop from the lower left side of the insulating substrate 3 a in the pages of FIG. 4 .
  • the beginning of the first conductor pattern 1 a is electrically connected to the outer electrode 4 a (see FIG. 1 ) via the wiring patterns 11 a .
  • a connection portion 31 a connected to the via conductor 31 is provided near the termination of the first conductor pattern 1 a .
  • a connection portion 32 a connected to the via conductor 32 is provided at a midpoint of the first conductor pattern 1 a.
  • the first conductor pattern 1 c being part of the first inductor L 1 is formed on the insulating substrate 3 c .
  • the first conductor pattern 1 c has the same shape as the shape of the first conductor pattern 1 a and is a hexagonal pattern of about a single counterclockwise loop from the lower left side of the insulating substrate 3 c in the pages of FIG. 4 .
  • the beginning of the first conductor pattern 1 c is electrically connected to the outer electrode 4 a (see FIG. 1 ) via the wiring patterns 11 c .
  • a connection portion 31 c connected to the via conductor 31 is provided near the termination of the first conductor pattern 1 c .
  • a connection portion 32 c connected to the via conductor 32 is provided at a midpoint of the first conductor pattern 1 c.
  • first inductor L 1 two coils of about a single turn are connected in parallel as follows: the first conductor patterns 1 a and 1 c are connected in parallel and the first conductor patterns 1 b and 1 d are connected in parallel; and the first conductor patterns 1 a and 1 c having been connected in parallel and the first conductor patterns 1 b and 1 d having been connected in parallel are connected in series.
  • the second conductor pattern 2 a being part of the second inductor L 2 is formed on the insulating substrate 3 e .
  • the second conductor pattern 2 a is an L-shaped pattern of about a half of a counterclockwise loop from the upper right side of the insulating substrate 3 e in the pages of FIG. 4 .
  • the beginning of the second conductor pattern 2 a is electrically connected to the outer electrode 4 b (see FIG. 1 ) via the wiring pattern 21 e .
  • a connection portion 33 a connected to the via conductor 33 is provided near the termination of the second conductor pattern 2 a.
  • the second conductor pattern 2 b being part of the second inductor L 2 is formed on the insulating substrate 3 f .
  • the second conductor pattern 2 b is a U-shaped pattern of about a three-quarter counterclockwise loop from the lower left side of the insulating substrate 3 f in the pages of FIG. 4 .
  • a connection portion 33 b connected to the via conductor 33 is provided near the beginning of the second conductor pattern 2 b .
  • a connection portion 34 a connected to the via conductor 34 is provided near the termination of the second conductor pattern 2 b .
  • a connection portion 35 a connected to the via conductor 35 is provided at a midpoint of the second conductor pattern 2 b.
  • the second conductor pattern 2 c being part of the second inductor L 2 is formed on the insulating substrate 3 g .
  • the second conductor pattern 2 c is a U-shaped pattern of about a three-quarter counterclockwise loop from near or from the upper center of the insulating substrate 3 g in the pages of FIG. 4 .
  • a connection portion 35 b connected to the via conductor 35 is provided near the beginning of the second conductor pattern 2 c .
  • a connection portion 36 a connected to the via conductor 36 is provided near the termination of the second conductor pattern 2 c .
  • a connection portion 34 b connected to the via conductor 34 is provided at a midpoint of the second conductor pattern 2 c.
  • the second conductor pattern 2 d being part of the second inductor L 2 is formed on the insulating substrate 3 h .
  • the second conductor pattern 2 d is an I-shaped pattern formed so as to extend from the lower right side to the upper side of the insulating substrate 3 h in the pages of FIG. 4 .
  • a connection portion 36 b connected to the via conductor 36 is provided near the beginning of the second conductor pattern 2 d .
  • a connection portion 37 a connected to a via conductor 37 is provided near the termination of the second conductor pattern 2 d.
  • the second inductor L 2 is included in an about two-turn coil in which the second conductor patterns 2 a to 2 d are connected in series.
  • the opening portion of the second inductor L 2 has a rectangular shape while the opening portion of the first inductor L 1 has a hexagonal shape.
  • the inductance of the second inductor L 2 can be increased by effectively utilizing a space inside the insulating body 3 .
  • the opening portion of the first inductor L 1 has a hexagonal shape, in plan view seen from the top surface side, the area by which the opening portions of the first inductor L 1 and the second inductor L 2 are superposed on each other can be changed, and accordingly, the coupling coefficient k can be adjusted.
  • the opening portion of the first inductor L 1 has a hexagonal shape, the inductance of the first inductor L 1 can be reduced, and accordingly, the bandpass characteristic of the filter device 100 can be improved.
  • the shape of the opening portion of the first inductor L 1 is not limited to the hexagonal shape. It is sufficient that the opening portion of the first inductor L 1 have a shape other than a rectangular shape.
  • the opening portion of the first inductor L 1 may have a polygonal shape such as an octagonal shape.
  • the electrode pattern 5 a (first electrode pattern) included in one of the electrodes of the capacitor C 1 is formed on the insulating substrate 3 i .
  • the electrode pattern 5 a is provided at a position on the right side of the insulating body 3 . That is, the electrode pattern 5 a is provided at a position so as to avoid superposition on the opening portion of the first inductor L 1 and the opening portion of the second inductor L 2 as much as possible. In other words, the capacitor does not substantially overlap with an opening of the first inductor or an opening of the second inductor.
  • the electrode pattern 5 a includes a connection portion 37 b connected to the via conductor 37 .
  • the electrode pattern 5 b is formed on the insulating substrate 3 j . In plan view seen from the top surface side, the electrode pattern 5 b is provided at a position superposed on the electrode pattern 5 a .
  • the electrode pattern 5 b is the floating electrode of the capacitor C 1 that is not electrically connected to the outer electrode 4 b (see FIG. 1 ).
  • the electrode pattern 5 c included in another electrode of the capacitor C 1 is formed on the insulating substrate 3 k .
  • the electrode pattern 5 c is provided at a position facing the electrode pattern 5 b .
  • the electrode pattern 5 c is electrically connected to the outer electrodes 4 b (see FIG. 1 ) at both the side surfaces facing with the wiring patterns 51 c interposed therebetween.
  • the electrode pattern 5 c includes a connection portion 39 a connected to the via conductor 39 .
  • the wiring pattern 52 is provided at a position on the left side of the insulating body 3 .
  • the wiring pattern 52 is electrically connected to the outer electrodes 4 a (see FIG. 1 ) on both the side surfaces facing each other with the wiring patterns 52 c interposed therebetween.
  • the wiring pattern 52 includes a connection portion 38 a connected to a via conductor 38 .
  • the electrode pattern 5 a , the electrode pattern 5 b , and the electrode pattern 5 c are included in a capacitor.
  • the insulating substrates 31 to 3 n are further provided in a lower layer of the capacitor C 1 .
  • the insulating substrate 31 includes the wiring pattern 53 including a connection portion 38 b connected to the via conductor 38 and the wiring pattern 54 including a connection portion 39 b connected to the via conductor 39 and a connection portion 41 a connected to the via conductor 41 .
  • the insulating substrate 3 m includes the wiring pattern 55 including a connection portion 38 c connected to the via conductor 38 and the wiring pattern 56 including a connection portion 41 b connected to the via conductor 41 .
  • the insulating substrate 3 n includes a connection portion 38 d connected to the via conductor 38 and the wiring pattern 56 including a connection portion 41 c connected to the via conductor 41 .
  • the via conductor 38 is electrically connected to the outer electrode 4 a provided on the bottom surface via the connection portion 38 d .
  • the via conductor 41 is electrically connected to the outer electrode 4 b provided on the bottom surface via the connection portion 41 c.
  • the third inductor L 3 includes the path extending from the wiring patterns 11 b and 11 d provided at a first end of the first inductor L 1 through the outer electrode 4 b on the side surface (first side surface) of the insulating body 3 , the electrode pattern 5 c of the capacitor C 1 , and the outer electrode 4 b on the side surface (second side surface) of the insulating body 3 , to the wiring pattern 21 e provided at a first end of the second inductor L 2 .
  • Embodiment 2 the configuration of a filter device to which a smaller inductance than the inductance of the third inductor L 3 according to Embodiment 1 is added is described.
  • FIG. 5 is a perspective view of a filter device 200 according to Embodiment 2.
  • the short edge direction of the filter device 200 is defined as the X direction
  • the long edge direction of the filter device 200 is defined as the Y direction
  • the height direction of the filter device 200 is defined as the Z direction.
  • the same elements as those of the filter device 100 illustrated in FIG. 1 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the filter device 200 is a rectangular parallelepiped-shaped chip component in which two inductors and a single capacitor are laminated in the Z direction.
  • the filter device 200 includes the insulating body 3 formed by laminating a plurality of insulating substrates (insulating body layers) on which the first conductor patterns of the first inductor L 1 , the second conductor patterns of the second inductor L 2 , and the electrode patterns of the capacitor C 1 are formed as illustrated in FIG. 5 .
  • the configurations of the first inductor L 1 and the capacitor C 1 of the filter device 200 are the same as those of the filter device 100 illustrated in FIG. 1
  • the configuration of the second inductor L 2 of the filter device 200 is different from that of the filter device 100 .
  • the plurality of second conductor patterns 2 a to 2 d are laminated such that the second conductor patterns 2 a to 2 d are in parallel to the main surface of the insulating body 3 , and the second conductor patterns 2 a to 2 d are electrically connected via the via conductors 33 to 36 .
  • the second conductor pattern 2 a and the outer electrode 4 b are electrically connected to each other via a wiring pattern 22 e at the side surface (first side surface) of the insulating body 3 .
  • the second conductor pattern 2 a and the outer electrode 4 a are not electrically connected to each other.
  • the third inductor L 3 includes a path extending from the wiring patterns 11 b and 11 d provided at the first end of the first inductor L 1 through the outer electrode 4 b on the side surface (first side surface) of the insulating body 3 , to the wiring pattern 22 e provided at a first end of the second inductor L 2 .
  • an inductor is formed only by the outer electrode 4 b provided on one of the side surfaces of the insulating body 3 . Accordingly, the inductance reduces compared to the case where the inductor is formed by outer electrodes 4 b provided on both of the side surfaces of the insulating body 3 illustrated in FIG. 1 .
  • the opening surface of the third inductor L 3 illustrated in FIG. 5 is formed in the XZ plane.
  • the magnetic coupling between the first inductor L 1 and the third inductor L 3 is weaker than the magnetic coupling between the first inductor L 1 and the second inductor L 2 .
  • the second inductor L 2 , the third inductor L 3 , and the capacitor C 1 are connected in series in the insulating body 3 and included in an LC series resonator. Accordingly, the filter device 200 produces an attenuation pole by using the LC series resonator and has a resonant frequency.
  • FIG. 6 is an exploded plan view illustrating the configuration of the filter device 200 according to Embodiment 2.
  • the configuration of the filter device 200 is the same as the configuration of the filter device 100 illustrated in FIG. 1 except for that the configuration of the second inductor L 2 is different from that of the filter device 100 .
  • exploded plan view of the capacitor C 1 is omitted from FIG. 6 , and the same elements as those of the filter device 100 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the second conductor pattern 2 a being part of the second inductor L 2 is formed on the insulating substrate 3 e .
  • the second conductor pattern 2 a is an L-shaped pattern of about a half of a clockwise loop from the lower right side of the insulating substrate 3 e in the pages of FIG. 6 .
  • the beginning of the second conductor pattern 2 a is electrically connected to the outer electrode 4 b (see FIG. 5 ) via the wiring pattern 22 e .
  • the connection portion 33 a connected to the via conductor 33 is provided at a midpoint of the termination of the second conductor pattern 2 a .
  • the directions of the current flowing through the second conductor pattern 2 a and the second conductor pattern 2 b are opposite to each other, and the inductance value of the second inductor L 2 reduces.
  • the second conductor pattern 2 a can extend in the upper side of the page of FIG. 6 and can be connected to the wiring pattern 22 e from the left side.
  • the directions of the current flowing through the second conductor pattern 2 a and the second conductor pattern 2 b are the same, and the inductance value of the second inductor L 2 increases compared to that of the pattern illustrated in FIG. 5 .
  • the inductance value may be adjusted by adding a pattern in the opposite direction to a connection position.
  • FIG. 7 is a graph illustrating the attenuation characteristic of the filter device 200 according to Embodiment 2. Referring to FIG. 7 , the horizontal axis represents the frequency and the vertical axis represents the attenuation characteristic. The attenuation increases downward in FIG. 3 .
  • the resonant frequency f0 is about 4.85 GHz in the filter device 100 and about 5.05 GHz in the filter device 200 . Accordingly, it can be understood from FIG.
  • the resonant frequency f0 of the filter device 200 increases. Furthermore, the coupling coefficient k does not vary between the filter device 100 and the filter device 200 , and accordingly, the widths of the respective attenuation poles illustrated in FIG. 7 are substantially the same.
  • the resonant frequency f0 of the filter device 200 is reduced compared to the resonant frequency f0 of the filter device without the third inductor L 3 .
  • Embodiment 3 the configuration of a filter device to which a greater inductance than the inductance of the third inductor L 3 according to Embodiment 1 is added is described.
  • FIG. 8 is a perspective view of a filter device 300 according to Embodiment 3.
  • the short edge direction of the filter device 300 is defined as the X direction
  • the long edge direction of the filter device 300 is defined as the Y direction
  • the height direction of the filter device 300 is defined as the Z direction.
  • the same elements as those of the filter device 100 illustrated in FIG. 1 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the filter device 300 is a rectangular parallelepiped-shaped chip component in which two inductors and a single capacitor are laminated in the Z direction.
  • the filter device 300 includes the insulating body 3 formed by laminating a plurality of insulating substrates (insulating body layers) on which the first conductor patterns of the first inductor L 1 , the second conductor patterns of the second inductor L 2 , and the electrode patterns of the capacitor C 1 are formed as illustrated in FIG. 8 .
  • the configurations of the first inductor L 1 and the second inductor L 2 of the filter device 300 are the same as those of the filter device 100 illustrated in FIG. 1 , the configuration of the capacitor C 1 of the filter device 300 is different from that of the filter device 100 .
  • the capacitor C 1 is formed by laminating the plurality of electrode patterns 5 a to 5 c below the second inductor L 2 with the insulating layers interposed therebetween.
  • the second conductor pattern 2 d (see FIG. 4 ) of the second inductor L 2 and the electrode pattern 5 a are electrically connected to each other via the via conductor 37 .
  • the electrode pattern 5 b is a floating electrode that is not electrically connected to the outer electrode 4 b , other wiring patterns, or the like.
  • the electrode pattern 5 c is electrically connected to the outer electrode 4 b via the wiring pattern 51 c at one of the side surfaces (first side surface) of the insulating body 3 .
  • the via conductor 41 electrically connected to the outer electrode 4 b is not provided in the electrode pattern 5 c . That is, the capacitor C 1 has neither a path through which the electricity flows from the outer electrode 4 b provided on the one of the side surfaces (first side surface) to the outer electrode 4 b provided on the other side surface (second side surface) via the electrode pattern 5 c and the wiring pattern 51 c nor a path through which the electricity flows from the outer electrode 4 b provided on one of the side surfaces to the outer electrode 4 b provided on the bottom surface via the via conductor 41 .
  • the third inductor L 3 includes a path extending from the wiring patterns 11 b and 11 d provided at a first end of the first inductor L 1 through the outer electrode 4 b provided on the side surface (first side surface), the outer electrode 4 b provided on the bottom surface, and the outer electrode 4 b provided on the side surface (second side surface) of the insulating body 3 , to the wiring pattern 21 e provided at the first end of the second inductor L 2 .
  • the inductor is formed by a path that passes through the outer electrodes 4 b provided in an outer-side portion of the insulating body 3 without passing through an inner-side portion of the insulating body 3 .
  • the inductance increases.
  • the opening surface of the third inductor L 3 illustrated in FIG. 8 is formed in the XZ plane.
  • the magnetic coupling between the first inductor L 1 and the third inductor L 3 is weaker than the magnetic coupling between the first inductor L 1 and the second inductor L 2 .
  • the second inductor L 2 , the third inductor L 3 , and the capacitor C 1 are connected in series in the insulating body 3 and included in an LC series resonator. Accordingly, the filter device 300 produces an attenuation pole by using the LC series resonator and has a resonant frequency.
  • FIG. 9 is an exploded plan view illustrating the configuration of the filter device 300 according to Embodiment 3.
  • the configuration of the filter device 300 is the same as the configuration of the filter device 300 illustrated in FIG. 1 except for that the configuration of the capacitor C 1 is different from that of the filter device 100 .
  • exploded plan views of the first inductor L 1 and the second inductor L 2 are omitted from FIG. 9 , and the same elements as those of the filter device 100 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the electrode pattern 5 c included in the other electrode of the capacitor C 1 is formed on the insulating substrate 3 k .
  • the electrode pattern 5 c is provided at a position facing the electrode pattern 5 b .
  • the electrode pattern 5 c is electrically connected to the outer electrode 4 b (see FIG. 8 ) at one of the side surfaces via the wiring patterns 51 c .
  • the electrode pattern 5 c is not electrically connected to the outer electrode 4 b (see FIG. 8 ) at the other side surface.
  • the wiring pattern 51 c may also extend toward the outer electrode 4 b at the other side surface to which the wiring pattern 51 c is not electrically connected.
  • the wiring pattern 52 is provided at a position on the left side of the insulating body 3 .
  • the wiring pattern 52 is electrically connected to the outer electrodes 4 a on both the side surfaces facing each other with the wiring patterns 52 c interposed therebetween.
  • the wiring pattern 52 includes the connection portion 38 a connected to the via conductor 38 .
  • the electrode pattern 5 a , the electrode pattern 5 b , and the electrode pattern 5 c are included in a capacitor.
  • the insulating substrates 31 to 3 n are further provided in the lower layer of the capacitor C 1 .
  • the insulating substrate 31 includes the wiring pattern 53 including the connection portion 38 b connected to the via conductor 38 .
  • the insulating substrate 3 m includes the wiring pattern 55 including the connection portion 38 c connected to the via conductor 38 .
  • the insulating substrate 3 n includes the connection portion 38 d connected to the via conductor 38 .
  • the via conductor 38 is electrically connected to the outer electrode 4 a provided on the bottom surface via the connection portion 38 d .
  • the filter device 300 does not include the wiring pattern 54 or 56 or the via conductor 39 or 41 provided in the filter device 100 illustrated in FIG. 1 .
  • FIG. 10 is a graph illustrating the attenuation characteristic of the filter device 300 according to Embodiment 3. Referring to FIG. 10 , the horizontal axis represents the frequency and the vertical axis represents the attenuation characteristic. The attenuation increases downward in FIG. 10 .
  • the resonant frequency f0 is about 4.85 GHz in the filter device 100 and about 4.50 GHz in the filter device 300 . Accordingly, it can be understood from FIG.
  • the coupling coefficient k does not vary between the filter device 100 and the filter device 300 , and accordingly, the widths of the respective attenuation poles illustrated in FIG. 10 are substantially the same.
  • the second path TL 2 is described as the short path.
  • the inductance of the second path TL 2 is reduced so as to be smaller than the mutual inductance M between the first inductor L 1 and the second inductor L 2
  • the second path TL 2 can be regarded as the short path.
  • the inductance of the second path TL 2 may be smaller than the mutual inductance M between the first inductor L 1 and the second inductor L 2 .
  • the magnitude relationship between the inductance of the first inductor L 1 and the inductance of the second inductor L 2 is not particularly described.
  • the inductance of the first inductor L 1 may be smaller than the inductance of the second inductor L 2 . In this way, loss of the entirety of the filter device can be reduced.
  • the first inductor L 1 is electrically connected to the outer electrode 4 b at the first conductor patterns 1 b and 1 d and the second inductor L 2 is electrically connected to the outer electrode 4 b at the second conductor pattern 2 a .
  • the conductor pattern for the electrical connection to the outer electrode 4 b is not limited to the first conductor pattern 1 b or 1 d or the second conductor pattern 2 a but may be another conductor pattern.
  • the inductance of the third inductor L 3 can be adjusted by changing the conductor pattern for the electrical connection to the outer electrode 4 b .
  • the length of the path included in the third inductor L 3 increases, and accordingly, the inductance increases.
  • the position where the first conductor patterns 1 b and 1 d and the outer electrode 4 b are electrically connected to each other or the position where the second conductor pattern 2 a and the outer electrode 4 b are electrically connected to each other is not particularly limited.
  • the coupling coefficient k can be changed by moving the connection position in the Y-axis direction. For example, when the connection position is provided near the center of the insulating body 3 , the areas of the opening portions of the first inductor L 1 and the second inductor L 2 reduce. Thus, the coupling coefficient k can be reduced. In contrast, when the connection position is provided near an end portion of the insulating body 3 , the areas of the opening portions of the first inductor L 1 and the second inductor L 2 increase. Thus, the coupling coefficient k can be increased.
  • FIG. 11 includes circuit diagrams of an antenna device 150 a and an antenna device 150 b according to Modification 1.
  • the same elements as those of the antenna device 150 illustrated in FIG. 2 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the antenna device 150 a illustrated in (a) of FIG. 11 includes the feeding circuit RF 1 , the filter device 100 , a matching circuit 110 , and the radiating element 155 .
  • the radiating element 155 and the feeding circuit RF 1 are connected to each other via wiring 101 .
  • the filter device 100 and the matching circuit 110 are connected in series with the wiring 101 .
  • the matching circuit 110 is provided between the feeding circuit RF 1 and the filter device 100 .
  • the matching circuit 110 is provided for matching the impedance with the radiating element 155 , the feeding circuit RF 1 , the filter device 100 , and the like.
  • the matching circuit 110 includes resistance, inductance, capacitance, and the like.
  • the matching circuit may be provided not only between the feeding circuit RF 1 and the filter device 100 but also between the filter device 100 and the radiating element 155 .
  • the antenna device 150 b illustrated in (b) of FIG. 11 includes the feeding circuit RF 1 , the filter device 100 , matching circuits 110 and 120 , and the radiating element 155 .
  • the antenna device 150 b further includes the matching circuit 120 between the filter device 100 and the radiating element 155 .
  • the matching circuit 120 is connected in series with the wiring 101 and provided for matching the impedance with the radiating element 155 , the feeding circuit RF 1 , the filter device 100 , and the like.
  • the matching circuit 120 includes resistance, inductance, capacitance, and the like.
  • the matching circuit 120 may have the same configuration as that of the matching circuit 110 or a different configuration from that of the matching circuit 110 .
  • the matching circuit 110 is provided between the feeding circuit RF 1 and the filter device 100 and the matching circuit 120 is provided between the filter device 100 and the radiating element 155 .
  • the antenna device 150 b may include only the matching circuit 120 .
  • the matching circuits 110 and 120 are connected in series with the wiring 101 .
  • at least one of the matching circuits 110 and 120 may be connected in parallel (connected in shunt) between the wiring 101 and the ground (GND).
  • the antenna device 150 in which, as illustrated in (b) of FIG. 2 , the filter device 100 is connected in series with the feeding circuit RF 1 and the radiating element 155 is described.
  • the antenna device including the filter device 100 is not limited to the antenna device 150 illustrated in (b) of FIG. 2 .
  • the antenna device may include the filter device 100 connected in parallel with the feeding circuit RF 1 .
  • FIG. 12 includes circuit diagrams of an antenna device 150 c and an antenna device 150 d according to Modification 2.
  • the same elements as those of the antenna device 150 illustrated in FIG. 2 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the antenna device 150 c illustrated in (a) FIG. 12 includes the feeding circuit RF 1 , the filter device 100 , and the radiating element 155 .
  • the radiating element 155 and the feeding circuit RF 1 are connected to each other via the wiring 101 .
  • the filter device 100 is connected in parallel between the wiring 101 and the GND. That is, the antenna device 150 c includes the filter device 100 in which the terminal P 1 (first terminal) is connected to the GND and the terminal P 2 (second terminal) is connected to the wiring 101 .
  • the antenna device 150 d illustrated in (b) of FIG. 12 includes the feeding circuit RF 1 , the filter device 100 , the matching circuits 110 and 120 , and the radiating element 155 .
  • the matching circuits 110 and 120 are connected in series with the wiring 102 to which the filter device 100 is connected in the antenna device 150 d .
  • the matching circuit 110 is connected between the GND and the filter device 100
  • the matching circuit 120 is connected between the filter device 100 and the wiring 101 .
  • the matching circuits 110 and 120 are provided for matching the impedance with the radiating element 155 , the feeding circuit RF 1 , the filter device 100 , and the like.
  • the matching circuits 110 and 120 include resistance, inductance, capacitance, and the like.
  • the matching circuits 110 and 120 may have the same configurations or different configurations.
  • the antenna device 150 in which, as illustrated in (b) of FIG. 2 , the filter device 100 is provided in the wiring 101 connecting the radiating element 155 and the feeding circuit RF 1 to each other is described.
  • the antenna device including the filter device 100 is not limited to the antenna device 150 illustrated in (b) of FIG. 2 .
  • the filter device 100 may be provided at the short point of the radiating element in the antenna device.
  • FIG. 13 includes circuit diagrams of an antenna device 150 e and an antenna device 150 f according to Modification 3.
  • the same elements as those of the antenna device 150 illustrated in FIG. 2 are denoted by the same reference numerals, thereby to avoid repetition of the detailed description.
  • the antenna device 150 e illustrated in (a) of FIG. 13 includes the feeding circuit RF 1 , the filter device 100 , and the radiating element 155 .
  • the radiating element 155 is, for example, an inverted-F antenna having a short point P 3 .
  • the short point P 3 is connected to the GND via wiring 103 .
  • the filter device 100 is not provided in the wiring 101 connecting the radiating element 155 and the feeding circuit RF 1 to each other but in the wiring 103 . That is, the antenna device 150 e includes the filter device 100 connected in parallel with the feeding circuit RF 1 . That is, the antenna device 150 e includes the filter device 100 in which the terminal P 1 (first terminal) is connected to the GND and the terminal P 2 (second terminal) is connected to the short point P 3 .
  • the antenna device 150 f illustrated in (b) of FIG. 13 includes the feeding circuit RF 1 , the filter device 100 , the matching circuits 110 and 120 , and the radiating element 155 .
  • the matching circuits 110 and 120 are connected in series with the wiring 103 to which the filter device 100 is connected in the antenna device 150 f .
  • the matching circuit 110 is connected between the GND and the filter device 100
  • the matching circuit 120 is connected between the filter device 100 and the short point P 3 of the radiating element 155 .
  • the matching circuits 110 and 120 are provided for matching the impedance with the radiating element 155 , the feeding circuit RF 1 , the filter device 100 , and the like.
  • the matching circuits 110 and 120 include resistance, inductance, capacitance, and the like.
  • the matching circuits 110 and 120 may have the same configurations or different configurations.
  • a filter device has an attenuation band.
  • the filter device includes
  • the series resonator includes
  • Magnetic coupling between the first inductor and the third inductor is weaker than magnetic coupling between the first inductor and the second inductor.
  • the filter device according to the present disclosure includes the third inductor with a weak magnetic coupling, a steep filter device having an attenuation pole in a low frequency band can be realized.
  • the insulating body includes
  • the third inductor is provided by utilizing part of the second outer electrode.
  • One end of the first inductor is electrically connected to the second outer electrode provided on the first side surface
  • the third inductor includes a path extending from the one end of the first inductor through the second outer electrode on the first side surface, the second electrode of the capacitor, and the second outer electrode on the second side surface to the one end of the second inductor.
  • One end of the first inductor is electrically connected to the second outer electrode provided on the first side surface, and
  • the third inductor includes a path extending from the one end of the first inductor through the second outer electrode on the first side surface to the one end of the second inductor.
  • One end of the first inductor is electrically connected to the second outer electrode provided on the first side surface, and
  • the third inductor includes a path extending from the one end of the first inductor through the second outer electrode on the first side surface, the second outer electrode on the first main surface, and the second outer electrode on the second side surface to the one end of the second inductor.
  • An antenna device is configured to be able to radiate a radio wave.
  • the antenna device includes
  • An antenna device configured to be able to radiate a radio wave.
  • the antenna device includes

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Filters And Equalizers (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
US19/351,353 2023-04-28 2025-10-07 Filter device and antenna device Pending US20260039268A1 (en)

Applications Claiming Priority (3)

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JP2023-074456 2023-04-28
JP2023074456 2023-04-28
PCT/JP2024/002365 WO2024224724A1 (ja) 2023-04-28 2024-01-26 フィルタ装置、およびアンテナ装置

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JPH0831755B2 (ja) * 1985-06-13 1996-03-27 松下電器産業株式会社 Ｌｃバンドパスフイルタ−
JP2529371B2 (ja) * 1988-12-12 1996-08-28 松下電器産業株式会社 Ｌｃバンドパスフィルタ
CN107210721B (zh) * 2015-02-02 2020-10-27 株式会社村田制作所 可变滤波电路、高频模块电路、以及通信装置
TW201742375A (zh) * 2016-05-17 2017-12-01 村田製作所股份有限公司 Ｌｃ濾波器

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